Artificial limb.



PATENTBD AUG. 2, 1904.

A. GAULT.

ARTIFICIAL LIME.

APPLICATION FILED OCT. 2a. 1903.

in 5 min f a $0 a MW y? 2 N0 MODEL N/T/YEJJEJ M 1+ Patented August 2, 1904.

PATENT OEEIcE.

ALEXANDER GAULT, OF MEDFORD, MINNESOTA.

ARTIFICIAL LIMB.

SPECIFICATION forming part of Letters Patent No. 766,686, dated August 2, 1904,

Application filed October 23, 1903. $erial No. 178,191. (No model.)

To all whom, it may concern.-

Be it known that I, ALEXANDER GAULT, of Medford, Steele county, Minnesota, have invented certain new and useful Improvements in Artificial Limbs, of which the following is a specification.

The object of my invention is to simplify and improve the artificial limb shown and described in Letters Patent of the United States granted to me February 26, 1901, N 0. 668,634.

The invention consists generally in various constructions and combinations, all as hereinafter described, and particularly pointed out in the claims.

In the accompanying drawings, forming part of this specification, Figure 1 is a side elevation of an artificial limb embodying my invention. Fig. 2 is a sectional view of the same. Fig. 3 is a similar view taken on the line y y of Fig. 2. Fig. 4 is a detail of the knee joint or hinge and manner of securing the same to the thigh-section. Fig. 5 is a section on the line .2 .2 of Fig. 2. Fig. 6 is a plan view of a hinged plate provided on the sole of the foot. Fig. 7 is an edge view of the same. Fig. 8 is a plan view of the plate provided in connection with the knee-joint. Figs. 9 and 10 are details of the device for locking the knee-joint to permit the person wearing the artificial limb to walk stiff-legged.

In the drawings, 2 represents the lower legsection below the knee provided with a foot portion 3 of any preferred size. A felt section I is provided at the forward end of the foot, and a plate 6 is secured to the felt section under the ball of the foot by bolts or other suitable means and is connected with a similar plate 7, located under the heel portion of the foot by a rib 8. These plates and their connecting-rib form a shank that is preferably made of aluminium on account of its great strength and light weight in comparison with other metals of the same bulk. The forward end of the plate 6 terminates under the ball of the foot, and the rear end of the plate 7 coincides with the rear edge of the heel portion, as shown in Fig. 2.

The shank is preferably concealed on the bottom by a felt sole 9. The foot portion 3 is provided with a recess or socket 10, adapted to receive a metallic box 11, wherein a hub 12, provided on the rib 8, is fitted. This hub is bored to receive a hardened-steel bushing 13, through which a pin 14 passes and also through the walls of the box 11 and forms a pivot for the shank on the foot. The pin 14 is tapered, as shown in Fig. 5, to permit its wear to be taken up, and it has a squared head at one end and a nut 15 at its opposite end that is provided with a slot 16, adapted to receive a screw-driver for the convenience of loosening or tightening the nut on said tapered pin. A washer 16 is preferably provided between the nut 15 and the wall of the box 11. As the pin 1 L wears by contacting with its bearings it can be rotated from time to time to present new and unworn surfaces. All these precautions of construction are taken to prevent any unnecessary lost motion in the joint and rattling of the parts. A hole 17 is provided in the hub 12, leading to the pin 14, through which oil may be introduced by bending the felt portion 4 at the instep away from its contact with the ankle part 3. The heel portion of the shank is provided with a bearing 18, that extends up in the recess 10 and supports a tapered pin 19, that fits within a bushing 20, having an oil-hole 21. The pin 19 is held from turning in its hearing by a lock-nut 22 and by loosening said nut can be given rotary or longitudinal adjustment to compensate for the wear of the joint.

Mounted upon the bushing is a hub 23, having an oil-hole arranged to register with the hole in the bushing and a threaded socket 24:, adapted to receive the threaded lower end of a rod 25, that extends up through a recess 26 in the foot portion 3,through a wall 27 and into a second recess 28 in the rear portion of the ankle, to which access may be had at the rear end of the leg portion 2. The rod passes through two blocks 29 and 30, both preferably of rubber, the former arranged within the recess 26, resting at its lower end upon a washer 31 and at its upper end bearing upon the lower side of the partition-wall 27. The block rests upon the upper side of said wall and is partially inclosed by a cap 32 and is held in place by a nut 33 on the upper end of the rod 25, between which nut and 100 cap I prefer to provide a metallic washerplate 34 and leather or rubber washers 35. The cap 32 will hold the block 30 in place and prevent it from spreading out at the sides, and the plate 34 will prevent the upper end of the rod from being drawn down too far should it be subjected to any sudden or unusual strain. It will be noted that the blocks 29 and 30 serve as double -acting springs, one being compressed when the tension is applied to draw the rod 25 in one direction and the other when the rod is drawn in the opposite direction. In other words, when the weight is placed on the forward portion of the foot in the act of walking the block 30 will be compressed, and when the weight is sustained on the heel portion of the foot the pressure will be applied to block 29. This manner of supporting the shank in the hollow of the foot and at the heel allows it to adjust itself to the different positions of the foot in the act of walking and conforms as nearly as possible in a device of this kind to the movement of the human ankle-joint. The rod 25 is adjustable, so that the forward end of the shank can be raised or lowered to suit the convenience of the person wearing the artificial limb.

When the wearer of the limb is seated, the rear portion of the shank on the heel-plate will yield sufiiciently to depress the toe portion of the foot and render the limb less liable to attract the attention of others, the parts,

conforming as nearly as possible to the bending and yielding of the human foot.

The upper end of the lower leg-section at the rear has an inclined surface 36, on which a fiat plate 37 is secured by means of bolts 38. This plate is provided with a slot 39 and with lugs 40, that fit sockets in the leg-section at the upper end of the surface 36. Beneath the plate 37 near the middle of the legsection, I provide a bearing-surface for the knee-joint, wherein a washer 41, of leather or other suitable material, is placed, and upon this washer I arrange transversely with respect to the leg-section a tubing 42, such as is employed in the construction of a bicycleframe, having upwardly-extending arms 43 at each end brazed thereon and a centrallyarranged stud 44, having a backwardly-turned pin 45, provided with a longitudinal slot 46. The stud 44 projects up through the slot 39 and is movable therein, and the arms 43 are secured to the lower portion of the thigh-section 47 by rivets or other suitable means, said thigh-section having an open lower end to receive the upper end of the leg-section. The thigh-section may be made of any suitable material; but I prefer to employ aluminium, as it is very tough and durable and will not crack or split, as a Wood construction is very apt to do. Furthermore, it is very light, can

be easily padded and formed to flare slightly from the bottom toward the top to permit the convenient insertion of the stump of the leg.

Beneath the rear portion of the plate 37 is a socket wherein a pipe 49 is arranged to receive a rod 50, having a U-shaped socket 51 inits upper end to engage a pin 52 in the slot 46. A spring 53 is coiled around the rod 50 within said pipe and is adapted to be compressed by the downward movement of said rod and to aid in straightening the kneejoint. WVhenever desired, the rod 50 can be pressed down by the hand, disengaging it from the pin 51 and allowing the joint to be used without the spring, and at such time the rod and spring can be removed through the slot 39.

The plate 37 is readily removable to allow access to the knee-joint bearing for the purpose of removing the leather washer or in other ways tightening or repairing the joint. To prevent the lower leg-section from swinging back too far, a bearing-surface 54 is provided at the upper end of the same, against which the stud 44 strikes when the joint isstraight and prevents the foot from backward movement.

It is sometimes desirable in walking through snow or in underbrush, where it would be difficult to control the lower swinging leg-section, to provide means whereby the wearer of the artificial limb can conveniently lock the kneejoint, rendering it stifl for the time being, and thus obviate the danger of the dragging legsection from tripping the wearer. This looking means consists of a stud 55, arranged within sockets 56 and 57 in the front of the leg-section and having a slot 58 in its inner end to receive a lever 59, that is pivoted at one end within a horizontal slot (see Fig. 9) in the leg-section and is held in the slot 58 by a pin 61. The free end of the lever 59 projects slightly beyond the end of the slot 60 and is adapted to be connected to a cord by means of which the wearer can manipulate the catch to lock or unlock the joint. The slot 60 (see Fig. 9) is of suflicient width at the free end of the lever 59 to allow the same to be oscillated and move the stud 55 longitudinally against the tension of a spring 62, that normally holds said stud in its forward position. The outer end of said stud is provided with a plate 63, fitting within a recess 64 in the leg-section and having a lug 65 that engages a catch 66 on the lower edge of the thigh-section. The lug 65 has a beveled face that permits the catch to slide over the same and snap in place to automatically lock the joint, which will be prevented from turning until the lever 59 is operated to withdraw the stud 55 and disengage the lug from the catch. As there will be more or less strain upon this locking device, and particularly the screws for fastening the plate 63 to the leg-section, I prefer to provide a second plate 67, overlapping the lower end of the first-named one and having fastening means, such as screws, that pass through both said plates into the leg-section.

From an examination of the drawings it will I on be noted that the thigh-section, except at its lower end, is entirely free from projections or obstructions, and consequently can be readily fitted to stumps of different length, and there is ample room within the thigh-section to provide any desired amount of padding to prevent the end of the stump from coming in contact with any portion of the knee-joint.

I claim as my invention 1. In an artificial limb, the combination, with the foot portion having a toe-section of yielding material, of a shank hinged near the middle of the foot on the underside and having a for\ 'ardly-extending part secured to said yielding section, a yielding" block provided in said foot portion and a rod connecting said block and said shank in the rear of its hinge on said foot portion.

2. In an artificial limb, the combination, with an ankle portion and a toe-section secured thereto, of a shank hinged to said ankle portion and having a rearwardly-extending plate forming the heel for the foot, springs provided within recesses in said ankle portion, a rod pivotally connected with said shank and whereon said springs are mounted, and a wall interposed between the contiguous ends of said springs.

3. In an artificial limb, the combination, with an ankle portion, of a shank hinged thereon, a felt toe-section secured to the forward end of said shank, the rear end of said felt section normally contacting with said ankle portion but being separable therefrom to expose the hinged joint, and a yielding connection interposed between the rear end of said shank and said ankle portion.

4. The combination, with a lower leg and foot portion, the former having recesses and a partition-wall between them, of a shank pivoted on said foot portion and extending back beneath the heel thereof, a rod pivotally connected to said shank and extending up through said recesses and said partition-wall, a spring device mounted on said rod within said recesses, one spring bearing on one surface of said wall and the other spring upon the opposite surface of said wall, for the purpose specified.

5. In an artificial limb, the combination, with the leg-section of a plate 40 having a slot 39 secured thereon, a tubing 42 provided in a suitable bearing beneath said plate and having arms 43, a thigh-section 47 \vhereto said arms are secured, a stud 44 provided on said tubing, and a stop 54 provided on the upper end of said leg-section in the path of said stud.

6. In an artificial limb, the combination, with the leg-section having a suitable kneejoint bearing, of a member 42 fitting within said bearing and provided with arms 43, a thigh-section 47 whcreto said arms are secured, a stud 44, a rod 50 connected with said stud and fitting within a socket in said legsection, and a spring provided between said rod and said leg-section.

7. In an artificial limb, the combination, with a lower leg-section having a knee-joint socket, of a member 42 fitting therein and provided with arms 43, a thigh-section secured to said arms, a stud 44 provided on said member 42, a pin on said stud and having a slot 46, a rod fitting within a socket in said legsection and having a forked end to engage a pin transversely arranged in said slot 46 and a spring provided between said rod and the bottom of said last-named socket.

8. In an artificial limb, the combination, with the leg-section, of a sliding spring-latch mounted therein, means for withdrawing said latch, a thigh-section hinged on said leg-section, and a catch provided on said thigh-section and arranged to engage said latch to lock said hinge.

9. In an artificial limb, the combination, with the leg-section, having a suitable socket, of a stud fitting therein and provided with a latch, a spring for normally holding said stud and latch in their forward position, a pivoted lever arranged to engage said stud to withdraw the same against the tension of said spring, a thigh member hinged to said legsection, and a catch provided on said thigh member and arranged to be engaged by said latch when said stud is projected.

10. In an artificial foot, the combination, with an ankle portion, of a yielding toe-section, a shank having an arched middle portion hinged to said ankle portion beneath the instep, and end plates, one extending forward beneath the ball of the foot and secured to said toe-section and the other forming the heel portion and having a yielding connection with said ankle portion.

In witness whereof I have hereunto set my hand this 13th day of October, 1903.

ALEXANDER GAULT.

In presence of RIo rARD PAUL, C. Ur. HANsoN. 

